Can't fill the gas tank

I have a 1989 Ford super duty stake body with 2 gas tanks. This is the second time this problem happened. I try to pump gas in the front tank and the nozzle keeps shutting off like it's full. I try different positions and the same thing. The back tank fills fine. I bought the truck in Jan. and there was no problem. This happened at 2 different stations. Any ideas?? Thanks Matt

I have a problem with my 1985 F-150 sometimes; you just have to play with the fueler nozzel - somtimes I leave it real far out to get it to fuel or have to go real slow. I think that the gas tank line in many of these trucks don't let the fuel flow down to the tank quick enough, thus tripping the auto shut off on the nozzel.

You said its a stake body. I think thats part of the problem if your filler tubes come out under the bed. I know that on my F350 with dump body, the fuel filler tubes are so shallow that they will barely except fuel without the backpressure shuting the pump off or fuel shooting out the filler. I have to be very careful or I end up soaked with diesel, I know this from experience, Ive learned to just take my time and listen for the gurgle when the tank is full and stand off to the side.